CI: install libltdl-dev

Required to manage an autoconf macro.

Reviewed-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

.github/actions/install-dependencies/action.yml

@@ -13,5 +13,5 @@ runs:
       sudo apt-mark hold grub-efi-amd64-bin grub-efi-amd64-signed
       sudo apt-get update
       sudo apt-get -y dist-upgrade
-      sudo apt-get -y install ubuntu-dev-tools automake autopoint xsltproc gettext expect byacc libtool libbsd-dev pkgconf
+      sudo apt-get -y install ubuntu-dev-tools automake autopoint xsltproc gettext expect byacc libtool libbsd-dev libltdl-dev pkgconf
       sudo apt-get -y build-dep shadow